Search Publications
Nature of Faint Radio Sources in GOODS-North and GOODS-South Fields. I. Spectral Index and Radio-FIR Correlation
Giavalisco, Mauro; Yun, Min S.; Kawabe, Ryohei +9 more
We present the first results from the deep and wide 5 GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North (σ = 3.5 µJy beam-1, synthesized beam size θ = 1.″47 × 1.″42, and 52 sources over 109 arcmin2) and GOODS-South (σ = 3.0 µJy beam-1, θ = 0.″98 × 0.″45, and 88 sources …
Unusual Plasma and Particle Signatures at Mars and STEREO-A Related to CME-CME Interaction
Dumbović, Mateja; Temmer, Manuela; Veronig, Astrid +15 more
On 2017 July 25 a multistep Forbush decrease (FD) with a remarkable total amplitude of more than 15% was observed by Mars Science Laboratory/Radiation Assessment Detector at Mars. We find that these particle signatures are related to very pronounced plasma and magnetic field signatures detected in situ by STEREO-A on 2017 July 24, with a higher-th…
HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main-sequence Stars
Anderson, Jay; van der Marel, Roeland P.; Wetzel, Andrew +7 more
The Halo Assembly in Lambda Cold Dark Matter: Observations in 7 Dimensions (HALO7D) data set consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope-measured proper motions of Milky Way halo main-sequence turnoff stars in the CANDELS fields. In this paper, the second in the HALO7D series, we present the proper motions for the HALO7D sam…
Binary Red Supergiants. II. Discovering and Characterizing B-type Companions
Massey, Philip; Levesque, Emily M.; Morrell, Nidia I. +1 more
The percentage of massive main-sequence OB stars in binary systems is thought to be as high as 100%. However, very few Galactic binary red supergiants (RSGs) have been identified, despite the fact that these stars are the evolved descendants of OB stars. As shown in our recent paper, binary RSGs will likely have B-type companions, as dictated by s…
Dust Continuum Emission and the Upper Limit Fluxes of Submillimeter Water Lines of the Protoplanetary Disk around HD 163296 Observed by ALMA
Walsh, Catherine; Nomura, Hideko; Tsukagoshi, Takashi +6 more
In this paper, we analyze the upper limit fluxes of submillimeter ortho-H2 16O 321 GHz, para-H2 18O 322 GHz, and HDO 335 GHz lines from the protoplanetary disk around the Herbig Ae star HD 163296, using the Atacama Large Millimeter/Submillimeter Array. These water lines are considered to be the best cand…
Planck Far-infrared Detection of Hyper Suprime-Cam Protoclusters at z ∼ 4: Hidden AGN and Star Formation Activity
Ono, Yoshiaki; Goto, Tomotsugu; Kodama, Tadayuki +11 more
We perform a stacking analysis of Planck, AKARI, Infrared Astronomical Satellite, Wide-field Infrared Survey Explorer, and Herschel images of the largest number of (candidate) protoclusters at z ∼ 3.8 selected from the Hyper Suprime-Cam Subaru Strategic Program. Stacking the images of the 179 candidate protoclusters, the combined infrared (IR) emi…
The Matter Beyond the Ring: The Recent Evolution of SN 1987A Observed by the Hubble Space Telescope
Larsson, J.; Sollerman, J.; Lundqvist, P. +14 more
The nearby SN 1987A offers a spatially resolved view of the evolution of a young supernova (SN) remnant. Here we present recent Hubble Space Telescope imaging observations of SN 1987A, which we use to study the evolution of the ejecta, the circumstellar equatorial ring (ER), and the increasing emission from material outside the ER. We find that th…
Multipoint Study of Successive Coronal Mass Ejections Driving Moderate Disturbances at 1 au
Poedts, Stefaan; Scolini, Camilla; West, Matthew J. +10 more
We analyze in this work the propagation and geoeffectiveness of four successive coronal mass ejections (CMEs) that erupted from the Sun during 2013 May 21-23 and were detected in interplanetary space by the Wind and/or STEREO-A spacecraft. All these CMEs featured critical aspects for understanding so-called “problem space weather storms” at Earth.…
Metal-poor Stars Observed with the Automated Planet Finder Telescope. I. Discovery of Five Carbon-enhanced Metal-poor Stars from LAMOST
Zhao, Gang; Placco, Vinicius M.; Li, Haining +6 more
We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of -3.3 < [Fe/H] < -2.4. These stars were selected from the LAMOST DR3 low-resolution (R ∼ 2000) spectroscopic database as metal-poor candidates and followed up with high-resolution spectroscopy (R ∼ 110,000) with the Lick/APF. Stellar paramet…
Spectral Evidence for Heating at Large Column Mass in Umbral Solar Flare Kernels. I. IRIS Near-UV Spectra of the X1 Solar Flare of 2014 October 25
Kowalski, Adam F.; De Pontieu, Bart; Kerr, Graham S. +5 more
The GOES X1 flare SOL2014-10-25T17:08:00 was a three-ribbon solar flare observed with the Interface Region Imaging Spectrograph (IRIS) in the near-UV (NUV) and far-UV. One of the flare ribbons crossed a sunspot umbra, producing a dramatic, ∼1000% increase in the NUV continuum radiation. We comprehensively analyze the UV spectral data of the umbral…